1. Technical Field
The present invention relates to occupant protection apparatuses for vehicles and in particular a vehicle occupant protection apparatus that protects an occupant in the event of a side collision.
2. Related Art
Vehicles are provided with various types of occupant protection apparatuses. Such occupant protection apparatuses include an airbag that inflates and deploys to restrain and protect an occupant in the event of a vehicle collision and a pretensioner that restrains and protects an occupant by tightening a seat belt instantaneously in the event of a vehicle collision.
An occupant protection apparatus disclosed in Japanese Unexamined Patent Application Publication (JP-A) No. 2006-88912 causes a determination unit to make a determination, based on an acceleration signal from an acceleration detector, as to whether or not a collision occurs and, if it is determined that a collision occurs, activates protection devices such as airbags and pretensioners.
An occupant protection apparatus disclosed in JP-A No. 2014-11-8035 has first and second sensors that detect an impact to a vehicle side and a collision unit that makes a determination of a collision by making a comparison between detection signals from the sensors and a determination threshold. A pretensioner is activated or is prohibited from activation in accordance with results from the comparison between detection signals from the first and second sensors and the determination threshold.
In the event of a vehicle collision, the occupant protection apparatuses disclosed in JP-A Nos. 2006-88912 and 2014-118035 activate the pretensioner to instantaneously restrain an occupant and prevent movement of the occupant due to an inertial force, thereby maintaining a clearance between the occupant and an impact area to prevent an increase in injury level that the occupant experiences.